Liquid boiler



Feb. 20, 1934. A. J. NERAD LIQUID BOILER Filed Sept. 17. 1928 InventorAnthony LlN eF'EidH, y Ma HLS Attorney.

Patented F eb. 20, 1934 UNITED STATES LIQUID Roman Anthony J. Nerad,

Schenectady to General Electric Company, a

New York mention of Application seas-l... 17, ms Serial No. mm:

4 Claims. (01. na -:12)

The present invention relates to boilers for generating vapor fromliquid and especially to boilers intended for vaporizing a liquid havinga high boiling point as compared with water and which may becomparatively heavy. Such a liquid is mercury, mercury vapor now beingutilized for driving elastic fluid turbines and for other purposes, suchas a heating agent in connection with industrial processes.

The invention relates particularly to boilers of the type such as thatdisclosed in the application of Emmet and Coulson, Sr. No. 306,486,filed of even date herewith and has for its object to provide animproved construction and arrangement in a boiler of this type.

For a consideration of what I believe to be novel and my invention,attention is directed to the accompanying description and the claimsappended thereto.

In the drawing Fig. 1 is a sectional view of a boiler structureembodying my invention, and Figs. 2 and 3 are detail sectional views ona larger scale.

Referring to the drawing, 1 indicates a boiler drum or casing and 2indicates boiler tubes depending from the lower portion thereof. Eachboiler tube 2 comprises an outer tube 3 which at its upper end is fixedin an opening in drum 1 and is welded thereto as is indicated at 4, anda core 5 which is located inside tube 3 and provides a central passage 6through which the liquid to be vaporized ilows to the bottom of thetube, and an annular passage 7 through which the liquid flows upward andin which it is vaporized. Core 5 may be formed from an. inner tube 8 andan outer tube 9 welded together at their upper and lower ends as isindicated at 10. The space between tubes 8 and 9 being filled with airpreferably, which forms a heat-insulating medium to prevent transfer ofheat to the liquid to be vaporized as it flows downward through corepassage 6. The core 5 is held in spaced relation to tube 3 to defineannular passage 7 by means of short, longitudinally-extendingprojections 11 which may be formed by forcing outwardly portions of thewall of core tube 9. At its lower end the core is held in spacedrelation with tube 3 by a suitable projection 12. Core 5 is held down intube 3 by means of a washer 13 which engages the top of the core and isprovided with ears 14 which are welded to the adjacent inner surface ofthe tube 3 as is indicated at 15.

Inside drum or casing 1 and located in spaced relation thereto, is a.battle plate 16 provided with 5 opening 17 through which a liquid to bevaporized is supplied to core passages 6. Baflle plate 16 is held inspaced relation to the adjacent surface of drum 1 by projections 18which may be in the form of heads on studs threaded into the baiileplate. Associated with the boiler structure are filler blocks 19 whichserve to occupy spaces within the drum so as to decrease the volumewhich is required to be filled with the liquid to be vaporized. 20indicates lagging for the boiler structure, which lagging may be fixedin position in any suitable manner.

The structure so far described is more fully illustrated and describedin the above-referred application of Emmet and Coulson and is to betaken as representing a specific type of construction to which myinvention may be applied. In

- connection with a boiler of the type so far described. the liquidmercury is fed through baflie plate passages 1'? to core passages 6 andthe vapor generated in boiler tubes 2 fiows from the annular passages 7at the tops of outer tube 3.

In connection with the operation of such a boiler, it is important thatthe flow of liquid through the baiile plate passages to the corepassages be continuous and uninterrupted, for should an interruption inthe flow to a core passage occur, it may result in burning out of thetube. For manufacturing reasons, and because of the effect of heat uponthe structure, it is not practical to form a rigid connection betweenthe upper ends of the cores and the baffle plate openings 1'7.

Specifically, the object of my invention is to provide an improvedconnection between the baffle plate passages 1'1 and the core passages 6for conveying the liquid to be vaporized from passages 17 to passages 6.

According to my invention, I connect each baffle plate passage 1'7 tothe corresponding core passage 6 by means of a sleeve 21, the connectionbetween the sleeve and the passages being of a character such that thereis provided a yieldable connection between the parts whereby they maymove angularly and preferably axially also relatively to each other to alimited extent while still maintaining a fluid-tight connection. To thisend sleeve 21 in the present instance is made somewhat smaller indiameter than the diameters of passages 17 and 6 and at its two ends itis provided with flanges or collars 22 and 23 which have 'flat surfacesof limited extent in an. axial direction which engage the surfaces ofthe passages 17 and 6. This forms, in substance, a sort of universaljoint. With this arrangement, a tube 2 may assume a slightly angularposition relatively to a passage 1'1 without afiecting adversely thetightness of the connection with the sleeve, a turning movement takingplace around one or both flanges at the ends of the sleeve. 5 mayalsotake place relative to baffle 16 and with the joint as arranged thenecessary tightness is maintained. It will thus be seen that warping ofthe tubes or baflie plate or slight misalignments or other relativemovements which may take place while the boiler is in operation will notdisrupt the connection between the passages 1'7 and the core passages 6.With this arrangement, also, passages 17 and the tube passages 6 neednot be accurately aligned initially insofar as the connection of them bymeans of the sleeves 21 is concerned.

In the operation of a boiler of this type, the vapors generated flowrapidly from the upper end of annular spaces 7 and are directed outwardbeneath the bottom of the baflie plate 16 while the liquid to bevaporized fiows continuously through the baiiie plate passages 1'7 tothe core passages. It is of utmost importance to prevent the flow ofvapor from the upper ends of the annular passages 7 from interfering inany way with the flow of liquid through the passages 17 to the corepassages 6. In a boiler with a large number of tubes this interferencemay be cumulative with the performance of the boiler seriously hampered.By my invention, the possibility of this occurring is, for all practicalpurposes, eliminated.

The sleeves 21 are held in the baflle plate passages 17 by means of keys24 located in slots in the wall or drum. Ordinarily the tubes arearranged in rows lengthwise of the drum and keys 24 may be in the formof strips laid in a continuous slot apertinent to all the sleeves of arow of tubes. Also, ordinar y. the baille plate 16 will be made insections of suitable length a number of the tubes of each row of tubesbeing connected to each baflle plate section.

By the use of my invention, it will be seen that in constructing theboiler, the boiler tubes may be assembled in the drum or casing 1 andwelded in position after which a battle plate section 16 may be put inplace and fastened in a suitable manner and then sleeves 21 inserted oneafter another through the bailie plate openings 17 into the corepassages 6, the holding keys then being put in position. Since sleeves21 may assume a slightly angular position, it is not essential that thepassages 17 be aligned accurately with core passages 6. And in fact froma practical manufacturing standpoint, this would be a very difllcultresult to accomplish. The use of the sleeves 21 serves to renderpracticable manufacture and A limited axial movement of the core.

assembly without dimculty of a boiler structure of this type. Thearrangement has substantial advantages also from a practical standpointin that it permits of the ready dismantling of the boiler structure forrepairs and makes it possible readily to replace one or more tubesshould it become necessary. In addition to the foregoing, thearrangement is one which can be manufactured and assembled at low cost.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is: A

1. In a boiler structure, the combination of a casing, boiler tubesconnected to the casing, a baflie plate in the casing provided withpassages for the flow of liquid to the boiler tubes, and conduit meansconnecting said passages to the boiler tubes, said conduit means having'at one end a universal and slip joint with the adjacent wall.

2. In a boiler structure, the combination of a casing, boiler tubesconnected to the casing, a battle plate in the casing provided withpassages for the flow of liquid to the boiler tubes, and conduit meansconnecting said passages to the boiler tubes, said conduit means havingat least at one end a universal joint connection with the adjacent wall.

3. In a boiler structure, the combination of a casing, boiler tubesconnected to the casing, a baflle plate in the casing provided withpassages for the flow of liquid to the boiler tubes, and sleevesconnecting said passages to the boiler tubes, said sleeves havingoutturned flanges of small axial length which engage the walls of theadjacent passages with a sliding fit whereby there are provideduniversal joint connections be-.

-turned flanges of small axial length at their lower ends which engagewalls of the cores with a sliding fit whereby there are provideduniversal joint connections between the sleeves and the passages.

ANTHONY J. NERAD.

